Blog for the RepRap project at www.reprap.org - a project to create an open-source self-copying 3D printer. To get all the early posts on this blog with all the images as a single PDF visit this page.

Thursday, November 29, 2007

Resin paste-extruder valve

The valve mechanism in the experimental paste extruder was a bit difficult to make as it needed some machining. I've now done an alternative that uses rapid prototyping to make a blank and then soft casting in a silicone mould to produce the final item. You can't quite use rapid prototyping for the whole thing because RP is not good at threads, and this has an M14 one.

The advantage of this approach is that once you have set it up you can make a lot of these devices quickly and easily by repeated casting.

It uses the trick of trapping nuts in the resin to give good retention of screwed-in parts - see the soft casting page again for details.